Position indicator and line behavior inconsistent between Song-Editor, Piano-Roll, Beat/Bassline and Automation Editor

All three of the Song-Editor, Piano-Roll and Automation Editor show the the position arrow/indicator in the timeline.
For the Song-Editor and the Piano-Roll the position arrow/indicator moves when you start playing the song from within them. For the Automation Editor it doesn't, it just stays at the leftmost position.

Also, only in the Song-Editor there is a position line that moves along the track when playing to show the current position in the track, this position line doesn't exist in the Piano-Roll and the Automation Editor. IMHO having the position line makes it a lot clearer what's currently being played, so I'd like to propose to add it to the Piano-Roll and Automation Editor as well.

Compare playback position handling in the Song-Editor, Piano-Roll, Beat/Bassline, and Automation Editor, focusing first on how the timeline indicator moves during playback. Done means the Automation Editor indicator follows playback and the Piano-Roll and Automation Editor show a moving position line like the Song-Editor.

Written by the indexing model from the issue text.